VISUALISE a telescope so miniscule that it fits into your eyeball. Now imagine implanting that Lilliputian-sized gadget, measuring just four millimetres in height, in somebody's eye – just behind the iris, in fact – to help them see better.
Smaller than a pea, the telescopic implant uses the most sophisticated micro-optical technology to magnify central vision images. This provides improved 'straight ahead' vision.
Now imagine being the first Irish patient to have that telescope implanted in your eye.
In March 2013, retired medical scientist and Sligo man, Michael O Brien, was that patient – and his surgeon, Dr David Keegan at the Mater Private Hospital, led the first team outside the USA trials sector in inserting a commercial telescopic implant.
O'Brien, now aged 80, had been struggling with failing sight for some nine years when, in 2013, his wife spotted a newspaper article about trials of the miniscule telescopic implant.
Following a routine eye examination back in 2004, O'Brien was eventually diagnosed with Age-Related Macular Degeneration (AMD), the leading cause of sight loss in people over the age of 50 in Ireland.
AMD affects the macula, a small part of the eye responsible for central vision which allows you to see detail.
Michael, it emerged, had the most common form of the condition, Dry AMD, which develops slowly, leading to a loss of central vision.
The father of three from Rosses Point, who has a family history of AMD – his mother had it and both of his sisters are also affected by the condition – was put on a course of medication.
Nevertheless, his sight continued to deteriorate: " I found I was closing my left eye to read the small print on the newspaper, and I was finding it more and more difficult to read and send text messages."
Over the years he met with a number of consultants and was told to maintain his regimen of medication and to avoid night driving.
In 2013 he allowed his licence to expire: "By now I felt I was in limbo. Although I was able to play golf still, I could not follow the trajectory of the ball. My friends would find it for me – they were well trained!
"I'd stopped reading by this stage – the last time I read the paper was in 2011, and that was with one eye closed.
"I could watch television, but only as long as I sat close to it. Reading text and emails was now impossible for me."
Then, in early 2013, his wife Jo read a small piece in the Irish Independent about a trial of telescopic implants in the UK.
Michael's daughter Deirdre, a nurse, investigated the situation and discovered that a surgeon was planning to offer the treatment in the Mater Private Hospital in Dublin.
Michael asked his daughter to see if he could have the treatment – and after a thorough assessment process, the answer was yes.
"I was the first patient to have the surgery. The operation on my right eye was scheduled for March 25th, 2013," he says.
It wasn't cheap – the implant cost €12,000.
"The operation took less than an hour. It was carried out under local anaesthetic and later the same evening I went home."
A long process of check-ups, reviews and rehabilitation – learning how to actually use the telescopic implant – followed. It was very much a matter of learning to use the different services now offered by his eyes.
"In the implanted eye, the device renders enlarged central vision images over a wide area of the retina to improve central vision, while the non-operated eye provides peripheral vision for mobility and orientation," explains Michael.
"The rehabilitation consisted of exercises to help with my reading and writing and basically getting both eyes working both individually and together at the same time. My brain had to retrain.
"For the first two weeks after the operation I didn't notice much of a difference, but after about three weeks there was a gradual improvement until eventually I started being able to write very slowly.
"I can now read big print and I got a new phone which has bigger text and buttons so I can text message, which is a relief. I can also use the ordinary house phone – I can now dial the number again.
"My glasses have had to be changed a few times, including recently, a special pair for golf, that prevents me from having double vision
"I can also watch television comfortably, as the eye with the telescope in it enlarges the picture up to three times.
"Driving is still not viable, but hopefully this will improve. I am still optimistic about the future, and hope to be back on the road.
"I can watch hurling matches on TV which I wasn't able to do before because I was not able to follow the ball. I'm definitely better than I was," says Michael, who later wrote an article about the operation for Converse, the scientific journal of the Academy of Medical Laboratory Science of which he is a past President.
It's not for everyone, admits Consultant Vitreo-retinal Surgeon David Keegan – it's primarily aimed at people who have had treatment for AMD and who have dry AMD or stable wet AMD, he explains.
"You can have it if you've already had treatment for the wet type, as long as it is stable for six months previously," he says.
The telescopic implant is intended for those for whom no other treatment available – generally, patients tend to be over 70, but it's possible to carry out the procedure on anybody over the age of 55.
"It's a high-tech, low-vision aid. It's essentially instead of using a magnifying glass or other hand-held device. It's basically for those for whom nothing else can be done," David Keegan explains.
The best description of the concept, he says, is that it's the right technology in the right patient – to date, five patients have successfully undergone this procedure, and Keegan feels that once it has become routine, he will be carrying out up to 100 operations a year.
"It's not for everybody but, for those to whom it is suited, it works very well." It's unsuitable for anyone who has had cataract surgery, for example.
"The technical aspect is that you take out the cataract and insert the telescope into where the cataract was – it's only for patients who have not had cataract surgery.
The selection criteria are rigorous, he says, and one of the biggest challenges for patients is learning how to use the device properly.
Says Mr Keegan: "There is a different size image coming in from both eyes, so the brain has to learn to focus on the larger image coming in from the telescope.
"So if a patient wants to read or watch the TV, they have to concentrate on the eye with the telescopic implant."
However, he continues, if the patient wants to navigate a room or walk around a house, he or she must focus on the vision of the other eye, because the peripheral vision in that eye is what is required. That's the challenge, but they get to grips with it.
"It's a big surgery and it's an expensive technology and you need to ensure that the right people get it. Otherwise, it's a waste of money. I say to patients that it's like buying a Ferrari and parking it in the drive and not using it."
Patients are encouraged to constantly practise using the implant until they start to use it unconsciously.
"It improves your vision. We don't make any claims that it does any more. It's for people who want to regain more vision independence. It will not get them back driving but it will get them back watching TV, reading their post and signing cheques."
What is a telescopic implant?
The tiny telescope is implanted inside one eye, behind the iris. Smaller than a pea, the telescopic implant uses micro-optical technology to magnify central vision images – "straight ahead" vision.
For patients, this offers the opportunity to increase their independence and re-engage in everyday activities. It also may help patients in social settings, as it may allow them to recognise faces of family and friends.
The telescopic implant is not a cure for end-stage AMD. It helps by improving vision through the use of magnification but it doesn't restore vision to the level it was before AMD.
How the telescopic implant works
Once implanted inside the eye, the telescope projects images from your central vision on to healthy areas, outside of the degenerated macula. Normally the healthy areas outside of the macula are used for peripheral or "side vision" but the size of the images are too small to compensate alone for the blind spot in the central vision.
But with the telescope the image is enlarged and reduces the effect of the blind spot.
What about the other eye?
End-Stage AMD affects detailed central vision in both eyes. It does not affect peripheral vision. Peripheral vision is low resolution or blurry. You can't use it to read, but you can use it to detect objects and movement. In the CentraSight treatment programme, a person uses the eye with the telescopic implant for detailed central vision, such as reading signs.
The other eye is used for peripheral vision. As part of the programme, the patients are trained to use the two eyes in different ways.
How the telescopic implant is used
The telescopic implant does not limit your natural eye movements, and does not require you to move your entire head. You can use natural eye movements to see things that are close and far away from you, such as reading printed materials or watching TV.
As a trade-off to improving central vision, the peripheral or side vision will be restricted in the eye with the implant. However, your peripheral vision will stay the same as before the surgery in your non-implanted eye.
Is it difficult to use?
One of the skills you need to learn is how to switch your viewing between the eye with the telescopic implant and the eye without the implant.
You will also need to wear glasses and may need to sometimes use a hand-held magnifier with the telescopic-implanted eye to read fine details clearly.
However, in general, less magnification will be needed after surgery.
Health & Living